An electro-chemical device such as a primary battery, a rechargeable battery, a solar cell, a capacitor, and the like generates electrical energy through an electro-chemical reaction, and is called an energy storage device and is used as a portable power source.
The electro-chemical device in general consists of electrodes (positive and negative electrodes), an electrolyte solution, a separator, an exterior material, and an electrode terminal. The electrode terminal is welded to the exterior material of a battery or protruded out of the exterior material and electrically connected with the electrodes, and thus delivers electrons inside and outside of the battery. On the other hand, the electrode terminal is used to electrically connect more than one battery.
As for the electrode terminal, nickel (Ni) generally has excellent welding workability and corrosion resistance but is expensive and has relatively lower electrical conductivity than other materials and thus is not appropriate for a battery requiring high power, and copper (Cu) has excellent electrical conductivity but weak corrosion characteristics. Accordingly, copper (Cu) plated with nickel (Ni) or a nickel (Ni) alloy on the surface of the copper (CU) is known to be used for the electrode terminal.
However, an electrode terminal having higher electrical conductivity and simultaneously excellent corrosion resistance to obtain a high power battery is still required.